The present invention is related to boric anhydride solutions and the use of these solutions as hardeners of resols.
Boric anhydride (B.sub.2 O.sub.3) is a product which has numerous uses including use as a fire-proofing agent, as a dehydrating agent, as a catalyst or as a co-catalyst. The product is in a solid form (particles, granular form, powders) and no solvent is known in which boric anhydride has an appreciable solubility at least equal to 5 percent by weight. In order to facilitate handling and dispersion of boric acid in reaction mixtures it is desired to use boric anhydride in liquid form such as in the form of solutions, preferably concentrated solutions. This is one object of the present invention.